His violent attack on Rihanna and other bad acts are indefensible. But why no similar shunning of Glen Campbell or even Charlie Sheen? Race seems to be in play.

Hosting the Independent Spirit Awards in February, comedian Seth Rogen took a swipe at both pop singer Chris Brown and the Grammys, passing it off as biting social commentary.

“At the Grammys,” he quipped, “you can literally beat the … out of a nominee and be asked to perform twice.”

Admittedly, Brown has made himself an easy target: In February 2009, he assaulted then-girlfriend Rihanna the day of the Grammys show, at which he was supposed to perform and she was a nominee, leaving her bloodied and bruised. He was sentenced to five years' probation and six months of community service, which he has since completed.

At Rogen’s remark, the crowd at the Spirit Awards erupted in applause. Twitter nearly went into meltdown trying to keep up with all the cyber high-fives transmitted. The reaction showed that the public, evidently unlike the programmers of the Grammy Awards show, weren’t ready to forget Brown’s violent behavior.

But why does Brown continue to be dogged by his violent outburst when others are apparently forgiven?

The dart thrown at Chris Brown, for instance, could just as easily have been aimed at Glen Campbell, who appeared at the 2012 Grammys, but in the role of beloved elder statesmen. Battling Alzheimer's and in the midst of a farewell tour, he received a sentimental embrace by the audience, who upheld him as a music icon and cultural exemplar.

But in her 1997 autobiography “Nickel Dreams”, singer Tanya Tucker alleged that physical abuse was a staple of her brief early ’80s affair with Campbell, when he was 42 and she was 21, with the violence often playing out in front of others.

Here's what she wrote of one especially brutal episode: “[F]inally Glen reared back his arm and brought his elbow down in my face, shearing off my two front teeth right at the roots.... I reached my hand up and felt my mouth, and there was a gaping hole where my teeth should have been.... I was without front teeth for a week, and from that time on.”

Although Campbell denied Tucker’s claims and was never prosecuted, he had discussed their stormy relationship in his own autobiography published three years earlier, “Rhinestone Cowboy,” where he wrote, “We even fought during sex once or twice.”

Not before, during or after the Grammys did anyone say a word about Campbell's alleged abusive past or suggest that he should not be allowed onstage because of it. Then why Chris Brown? Because it’s recent? Because, unlike Campbell, he was prosecuted? Because Brown is his own worst enemy, prolonging the controversy with his behavior and his songs?

Or is it because Chris Brown is black? Bringing race into the equation will elicit groans, but the idea can’t be summarily dismissed. The Chris Brown-Rihanna episode brings to mind a similar scenario that derailed the reputation of rock ’n’ roll forefather Ike Turner, who was pilloried for his abusive behavior toward former wife Tina Turner, allegations that he denied.

Ike’s violence was outlined in Tina Turner’s 1986 autobiography “I, Tina,” a bestseller that penetrated popular consciousness in a way the country stars’ confessionals did not. Tina Turner was the ruling queen of pop when her book dropped and had secured iconic status by the time it was turned into the hit 1993 film “What’s Love Got to Do With It,” which disseminated the story on a scale the book never could have. Though he was never prosecuted for the abuse, Ike Turner’s reputation was decimated after the book came out, and he returned to form with two well-received albums only a few years before he died in 2007.

It’s a given that Turner would never have been as warmly embraced as Campbell if he’d appeared on the Grammys. Is there a double standard? There seems to be similar discrepancies when you look at the world of actors.

If you Google the words “Charlie Sheen” and “domestic violence,” the Internet gently weeps. Yet Sheen's well-documented fisticuffs-on-females (restraining orders from ex-wives; allegations from girlfriends and sex workers, alike, that he battered them) have not resulted in his name being synonymous with domestic violence except in an excusatory wink-and-nudge kind of way. A snickering humor trails his persona, as demonstrated in a “Comedy Central Roast” in his honor last year, where a lot of the night’s humor hinged on his out-of-control rep.

Imagine the outcry if Brown made light of his public persona the way Sheen does with his new TV series “Anger Management.”